Introduction
Conditional expressions, involving keywords such as if and else, provide JavaScript programs with the ability to perform different actions depending on a Boolean condition: true or false. This section covers the use of JavaScript conditionals, Boolean logic, and ternary statements.
Syntax
- if (condition) statement;
- if (condition) statement_1, statement_2, ..., statement_n;
- if (condition) {
statement
}
- if (condition) {
statement_1;
statement_2;
...
statement_n;
}
- if (condition) {
statement
} else {
statement
}
- if (condition) {
statement
} else if (condition) {
statement
} else {
statement
}
- switch (expression) {
case value1:
statement
[break;]
case value2:
statement
[break;]
case valueN:
statement
[break;]
default:
statement
[break;]
}
- condition ? value_for_true : value_for_false;
Conditions can break normal program flow by executing code based on the value of an expression. In JavaScript, this means using if
, else if
and else
statements and ternary operators.